计算总销售额增值税

Question

我需要计算总销售额的总增值税额（总销售额的15％）。 IM与此查询挣扎我第一次尝试了选择和随后没有工作 - >

SELECT SUM(price) AS total_sales, 
     SUM(price) * 0.15 AS fifteen_percent 
FROM sales; 

这里是产品表

这里的图片销售的图片表

任何帮助将不胜感激！，谢谢。

Answer 1

SELECT SUM(price*quantity) AS total_sales, 
     SUM(price*quantity) * 0.15 AS fifteen_percent 
FROM sales 
JOIN products ON sales.prod_id = products.prod_id; 

Answer 2

Wawrzyniec是正确的，但您也可以使用窗口函数进行聚合。

  SELECT DISTINCT prod_name, 
          SUM(price) OVER(PARTITION BY prod_name) * quantity as total_sales, 
          (SUM(price) OVER(PARTITION BY prod_name) * quantity) * 0.15 as fifteen_percent  
      FROM sales 
      INNER JOIN products ON sales.prod_id = products.prod_id;